Loading of cytosolic nitrite into the chloroplast in nitrate assimilation of rice was modified by introducing gene for chloroplastic nitrite transport from cucumber. Rice (Oryza sativa L. japonica cv. Nipponbare) was transformed with a cDNA (CsNitr1-L) that encodes a nitrite transporter of cucumber under the control of the CaMV35S promoter. CsNitr1-L transgenic rice grown by hydroponics with nitrate supplied as the sole nitrogen source grew as well as plants grown with ammonia. In contrast the growth of the untransformed or mock-transformed control rice was retarded on nitrate-containing medium by about 60% compared to plants grown with ammonia. Nitrite was not beneficial to the growth of the untransformed or mock-transformed control rice but sustained that of CsNitr1-L transgenic rice. Low steady-state concentration of nitrite in leaves as well as delayed non-photochemical quenching of chlorophyll fluorescence in CsNitr1-L transgenic rice seems indicative of higher nitrite use in chloroplasts.